Here, "skipping" refers to the lexer not emitting any tokens for portions of
the file within an #if condition (or similar) that evaluates to false.
Previously, the lexer had a special <SKIP> start condition used to control
this skipping. This start condition was not handled like a normal start
condition. Instead, there was a particularly ugly block of code set to be
included at the top of the generated lexing loop that would change from
<INITIAL> to <SKIP> or from <SKIP> to <INITIAL> depending on various pieces of
parser state, (such as parser->skip_state and parser->lexing_directive).
Not only was that an ugly approach, but the <SKIP> start condition was
complicating several glcpp bug fixes I attempted recently that want to use
start conditions for other purposes, (such as a new <HASH> start condition).
The recently added RETURN_TOKEN macro gives us a convenient way to implement
skipping without using a lexer start condition. Now, at the top of the
generated lexer, we examine all the necessary parser state and set a new
parser->skipping bit. Then, in RETURN_TOKEN, we examine parser->skipping to
determine whether to actually emit the token or not.
Besides this, there are only a couple of other places where we need to examine
the skipping bit (other than when returning a token):
* To avoid emitting an error for #error if skipped.
* To avoid entering the <DEFINE> start condition for a #define that is
skipped.
With all of this in place in the present commit, there are hopefully no
behavioral changes with this patch, ("make check" still passes all of the
glcpp tests at least).
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
The glcpp parser is line-based, so it needs to see a NEWLINE token at the end
of each line. This causes a trick for files that end without a final newline.
Previously, the lexer for glcpp punted in this case by unconditionally
returning a NEWLINE token at end-of-file, (causing most files to have an extra
blank line at the end). Here, we refine this by lexing end-of-file as a
NEWLINE token only if the immediately preceding token was not a NEWLINE token.
The patch is a minor change that only looks huge for two reasons:
1. Almost all glcpp test result ".expected" files are updated to drop
the extra newline.
2. All return statements from the lexer are adjusted to use a new
RETURN_TOKEN macro that tracks the last-token-was-a-newline state.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
While writing the previous commit message, I just felt bad documenting the
shortcoming of the change, (that undefined macro names would not be reported
in error messages).
Fix this by preserving the first-encounterd undefined macro name and reporting
that in any resulting error message.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The GLSL ES Specification 3.00.4 says:
#if, #ifdef, #ifndef, #else, #elif, and #endif are defined to operate
as for C++ except for the following:
...
• Undefined identifiers not consumed by the defined operator do not
default to '0'. Use of such identifiers causes an error.
[Page 11 (page 127 of the PDF file)]
as well as:
The semantics of applying operators in the preprocessor match those
standard in the C++ preprocessor with the following exceptions:
• The 2nd operand in a logical and ('&&') operation is evaluated if
and only if the 1st operand evaluates to non-zero.
• The 2nd operand in a logical or ('||') operation is evaluated if
and only if the 1st operand evaluates to zero.
If an operand is not evaluated, the presence of undefined identifiers
in the operand will not cause an error.
(Note that neither of these deviations from C++ preprocessor behavior apply to
non-ES GLSL, at least as of specfication version 4.30.6).
The first portion of this, (generating an error for an undefined macro in an
(short-circuiting to squelch errors), was not implemented previously, but is
implemented in this commit.
A test is added for "make check" to ensure this behavior.
Note: The change as implemented does make the error message a bit less
precise, (it just states that an undefined macro was encountered, but not the
name of the macro).
This commit fixes the following Khronos GLES3 conformance test:
undefined_identifiers.valid_undefined_identifier_1_vertex
undefined_identifiers.valid_undefined_identifier_1_fragment
undefined_identifiers.valid_undefined_identifier_2_vertex
undefined_identifiers.valid_undefined_identifier_2_fragment
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Previously, a line such as:
#else garbage
would flag an error if it followed "#if 0", but not if it followed "#if 1".
We fix this by setting a new bit of state (lexing_else) that allows the lexer
to defer switching to the <SKIP> start state until after the NEWLINE following
the #else directive.
A new test case is added for:
#if 1
#else garbage
#endif
which was untested before, (and did not generate the desired error).
This fixes the following Khronos GLES3 CTS tests:
tokens_after_else_vertex
tokens_after_else_fragment
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Fixes a regression since b2d1c579 where ES shaders without a #version
declaration would fail to compile if their precision declaration was
wrapped in the standard #ifdef GL_ES check.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=74066
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
The check was in the wrong place, such that if a shader incorrectly put
a preprocessor token before the #version declaration, the version would
be resolved twice, leading to a segmentation fault when attempting to
redefine the __VERSION__ macro.
#extension GL_ARB_sample_shading: require
#version 130
void main() {}
Also, rename glcpp_parser_resolve_version to
glcpp_parser_resolve_implicit_version to avoid confusion.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Carl Worth <cworth@cworth.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Instead of defining preprocessor macros in glcpp_parser_create based on
the GL API, wait until the shader version has been resolved. Doing this
allows us to correctly set (and not set) preprocessor macros for
extensions allowed by the API but not the shader, as in the case of
ARB_ES3_compatibility.
The shader version has been resolved when the preprocessor encounters
the first preprocessor token, since the GLSL spec says
"The #version directive must occur in a shader before anything else,
except for comments and white space."
Specifically, if a #version token is found the version is known
explicitly, and if any other preprocessor token is found then the GLSL
version is implicitly 1.10.
Cc: mesa-stable@lists.freedesktop.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71630
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
The preprocessor currently accepts multiple else/elif-groups
per if-section. The GLSL-preprocessor is defined by the C++
specification, which defines the following parse-rule:
if-section:
if-group elif-groups(opt) else-group(opt) endif-line
This clearly only allows a single else-group, that has to come
after any elif-groups.
So let's modify the code to follow the specification. Add test
to prevent regressions.
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Carl Worth <cworth@cworth.org>
Cc: 10.0 <mesa-stable@lists.freedesktop.org>
The preprocessor has always replaced multi-line comments with a single space
character, (as required by the specification), but as of commit
bd55ba568b the lexer also emitted a NEWLINE
token for each newline within the comment, (in order to preserve line
numbers).
The emitting of NEWLINE tokens within the comment broke the rule of "replace a
multi-line comment with a single space" as could be exposed by code like the
following:
#define FOO a/*
*/b
FOO
Prior to commit bd55ba568b, this code defined
the macro FOO as "a b" as desired. Since that commit, this code instead
defines FOO as "a" and leaves a stray "b" in the output.
In this commit, we fix this by not emitting the NEWLINE tokens while lexing
the comment, but instead merely counting them in the commented_newlines
variable. Then, when the lexer next encounters a non-commented newline it
switches to a NEWLINE_CATCHUP state to emit as many NEWLINE tokens as
necessary (so that subsequent parsing stages still generate correct line
numbers).
Of course, it would have been more clear if we could have written a loop to
emit all the newlines, but flex conventions prevent that, (we must use
"return" for each token we emit).
It similarly would have been clear to have a new rule restricted to the
<NEWLINE_CATCHUP> state with an action much like the body of this if
condition. The problem with that is that this rule must not consume any
characters. It might be possible to write a rule that matches a single
lookahead of any character, but then we would also need an additional rule to
ensure for the <EOF> case where there are no additional characters available
for the lookahead to match.
Given those considerations, and given that the SKIP-state manipulation already
involves a code block at the top of the lexer function, before any rules, it
seems best to me to go with the implementation here which adds a similar
pre-rule code block for the NEWLINE_CATCHUP.
Finally, this commit also changes the expected output of a few, existing glcpp
tests. The change here is that the space character resulting from the
multi-line comment is now emitted before the newlines corresponding to that
comment. (Previously, the newlines were emitted first, and the space character
afterward.)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=72686
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
As the preprocessor becomes more sophisticated and gains more optional
behavior, it's easiest to just pass the GL context pointer to it so that
it can examine any fields there that it needs to (such as API version,
or the state of any driconf options, etc.).
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This can be triggered either by creation of a GLES context (with
api == API_OPENGLES2) or else by a #version directive with version
value 100 or with a string of "es" following the version value.
There's no behavioral change with this commit—just preparation for ES-specific
behavior in the preprocessor in the future.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
This symbol with dricore escapes into the namespace, its too generic,
we should prefix it with something just to be nice.
Should be applied to stable + 9.0
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The GLSL specification requires that #line directives be interpreted
after macro expansion. Our existing implementation of #line macros in
the lexer prevents conformance on this point.
Moving the handling of #line from the lexer to the parser gives us the
macro expansion we need. An additional benefit is that the
preprocessor also now supports comments on the same line as #line
directives.
Finally, the preprocessor now emits the (fully-macro-expanded) #line
directives into the output. This allows the full GLSL compiler to also
see and interpret these directives so it can also generate correct
line numbers in error messages.
Signed-off-by: Carl Worth <cworth@cworth.org>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The ralloc string appending functions were originally intended for
simple, non-hot-path uses like printing to an info log.
Cuts Unigine Tropics load time by around 20% (6 seconds).
v2: Avoid strlen() on every newline, too.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com> [v1]
Acked-by: José Fonseca <jfonseca@vmware.com> [v1]
Calling exit() on a memory failure probably made sense for the
standalone preprocessor, but doesn't seem too appealing as part of
the GL library. Also, we don't use it in the main compiler.
In both the preprocessor and in the compiler proper, we use a custom
yyltype struct to allow tracking the source-string number in addition
to line and column. However, we were previously relying on bison's
default initialization of the yyltype struct which of course is not
aware of the source field and leaves it uninitialized.
We fix this by defining our own YYLLOC_DEFAULT macro expanding on the
default version (as appears in the bison manual) and adding
initialization of yylloc.source.
